JPH0666227B2 - Capacitor - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacitor used in various electronic devices.

2. Description of the Related Art Capacitors made of plastic films, metallized films, ceramics, etc. have been used as dielectrics.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention provides a new type capacitor using a thin film obtained by electrolytic polymerization without incorporating the above-mentioned dielectric layer.

Means for Solving the Problems The present invention is directed to vacuum deposition of a silicon monoxide thin film on one surface of a conductor or a semiconductor characteristic region of a polymerized thin film obtained by electrolytic polymerization of thiophene or a derivative thereof, and an aluminum electrode stacked thereon. And an electrode made of a metal different from aluminum is directly attached to the other surface.

Incidentally, the above-mentioned different metal electrode may be used as it is as a polymer adhering material used as a positive electrode in the shape of a foil or the like during electrolytic polymerization, or by removing the polymer film from the metal foil or the like. Alternatively, the metal film electrode may be newly formed by the vapor deposition method.

Further, these electropolymerized films are washed with pure water, a pure solvent or the like after the film formation to remove free salts, residual solvent, unreacted monomers and the like, and after drying, the above-mentioned processing is performed.

Examples of the thiophene derivative include methylthiophene, ethylthiophene, isopropylthiophene, and the like. Salts used as a supporting electrolyte during electrolytic polymerization include lithium borofluoride, paratoluenesulfonate, silver perchlorate, lithium perchlorate, and chloride. Copper, borofluorinated tetrabutylamine,
There are tetrabutylamine perchlorate and the like, which are used alone or in combination. Solvents include benzonitrile, acetonitrile, nitrobenzene, orthodichlorobenzene, dimethylsulfate, water and the like.

Action The inventors of the present invention formed a silicon monoxide thin film on one surface of a conductor or semiconductor characteristic region of a polymerized thin film of phophen and its derivative obtained by an electrolytic polymerization method by a vacuum vapor deposition method, and superimpose aluminum on the thin film. As a result of various experiments and researches on the system formed by vacuum evaporation, etc., in the system in which the above-mentioned two-layer thin film is formed on one surface and a metal other than aluminum is directly attached to the other surface, it is extremely large due to the electrode action. It was confirmed that a capacitor having a small capacity and a small leakage electrode was obtained, and that it showed a much higher withstand voltage than a system without a silicon monoxide film. It was also confirmed at the same time that the silicon monoxide thin film did not contribute to the excellent dielectric properties of these capacitors, but that this property was achieved due to the electrode action of the electrolytically polymerized film.

In addition, it is preferable to use a metal having a work function larger than that of aluminum as the above-mentioned different metal species.

Example The configuration and characteristics of the capacitor according to the example are shown in the table.
Each of the thiophene and methylthiophene polymers used here has a film thickness of 5 μm and is electropolymerized with an acetonitrile-lithium borofluoride system and a benzonitrile-lithium perchlorate system, respectively, and has a salt / solvent ratio (ratio). The monomers / solvents (ratio) were both 2 g / 180 g (ratio). Electrode B
The Pt, Ni, and Co foils used for all are 6 μm thick. These are those using the positive electrode as it was at the time of polymerization. The silicon monoxide film was formed by the vacuum evaporation method, and the film thickness is shown in the Sio thickness column.

These capacitors are polar and a high withstand voltage is sometimes obtained when the aluminum electrode side is positive, and the values in the table are the values at this time.

As is clear from the table, these capacitors show extremely large capacitance, their leakage current is small, and their withstand voltage is also greatly improved. Furthermore, the film thickness of the polymerized film can be controlled in an electrical quantity by setting the conditions during electrolysis, and a uniform ultra-thin film can be obtained.
It was possible to obtain a long film or a wide film having a thickness of m or less. Even with this film thickness, the various properties shown in the table were maintained, and some properties were even improved. With this film, we were able to manufacture capacitors with a wound structure and a laminated structure.

Similar results were obtained with other derivative polymer films and electrode material systems.

EFFECTS OF THE INVENTION According to the present invention, due to the electrode effect of the thiophene or its derivative polymerized film, a capacitor having a large capacity, a small current and a high withstand voltage can be obtained. A compact, lightweight, dry type capacitor can be obtained.

Claims (1)

[Claims] 1. A silicon monoxide thin film is vapor-deposited on one surface of a polymer film obtained by electrolytic polymerization of thiophene or a derivative thereof,
A capacitor, wherein an electrode made of aluminum is provided on the vapor-deposited film surface of the silicon monoxide thin film, and an electrode made of a metal different from the electrode is provided on the other surface of the polymer film.